Synthesis of moxifloxacin–Au (III) and Ag (I) metal complexes and their biological activities

Multifunctional moxifloxacin and essential oil loaded sodium alginate/thiolated karaya gum hydrogel dressings for improved wound healing

Numerous efforts have been done to develop wound dressings for effective wound treatment, remains a considerable challenge. The aim of current research work was to prepare multifunctional sodium alginate/thiolated karaya gum hydrogel dressings containing moxifloxacin in combination with artemesia/cedarwood essential oil. Thiolation of karaya gum was achieved by esterification reaction with 3 mercapto-propionic acid and synthesis of blended sodium alginate and thiolated karaya gum hydrogel films without (S1/TK1) and with moxifloxacin and artemesia/cedarwood oil (S1/TK1.DA1, S1/TK1.DC1) was achieved using solvent casting technique and were evaluated for fourier transform infrared spectrum and thermogravimetric analysis. Increasing the concentration of thiolated karaya gum substantially enhanced the bioadhesion, with a 350 % increase in bioadhesion-force and 353 % improvement in bond-strength while exhibiting balanced mechanical properties with an increase rate of 166 % in tensile strength and 73 % in percent-elongation. Incorporation of both moxifloxacin and artemesia/cedarwood oil also considerably enhanced the antibacterial activity of Optimized S1/TK1.DA1 and S1/TK1.DC1 formulations by 286 % and 253 % against s. aureus and 367 % and 269 % against e. coli respectively. Furthermore 2, 2 - di phenyl picryl hydrazyl (DPPH) and superoxide anion scavenging potential of S1/TK1.DA1 and S1/TK1.DC1 were enhanced by 1587 %, 1379 % and by 1384 % and 1245 % respectively. In vivo wound healing efficacy in cutaneous rat model also confirmed almost complete wound closure (≈ 99 %), collagen deposition and anti-inflammatory activity, enabling rapid wound recovery in twelve days. In conclusion, prepared hydrogel dressings might be an outstanding choice for wound healing applications.

Development and in vitro-in vivo evaluation of ocular insert containing ketorolac tromethamine and moxifloxacin hydrochloride

PURPOSE

Conjunctivitis is a common eye disorder that causes swelling and inflammation of the conjunctiva. Topical dosage form containing antibiotics and non-steroidal anti-inflammatory drugs are prescribed for the treatment and in order to overcome problems of conventional dosage forms the present study aims to develop an ocular insert containing moxifloxacin HCl and ketorolac tromethamine.

METHODS

Insert was prepared by a solvent casting method by taking different polymers PVA, PVP K-30, and a combination of both as film-forming polymer, and glycerol as a plasticizer and characterized by various parameters like thickness, folding endurance, pH, swelling index, drug content, mechanical properties, in vitro and in vivo release study.

RESULTS

The formulation prepared by a combination of both polymers demonstrated significantly improved properties including % elongation, tensile strength, swelling index, drug content and drug release compared to the formulation made with single polymer. The in vitro release data indicated that the batch R8 exhibited sustain release of drug (85% release in 10 hr) and following the Higuchi model for release kinetics. In vivo, study in rabbit eyes revealed the sustained release of the drug up to 16 hr with a good correlation between in vitro and in vivo release data.

CONCLUSION

From the study, it can be concluded that the developed ocular insert can be a promising formulation for rational therapy of conjunctivitis.

Fluoroquinolone-Based Organic Salts (GUMBOS) with Antibacterial Potential

Antimicrobial resistance is a silent pandemic considered a public health concern worldwide. Strategic therapies are needed to replace antibacterials that are now ineffective. One approach entails the use of well-known antibacterials along with adjuvants that possess non-antibiotic properties but can extend the lifespan and enhance the effectiveness of the treatment, while also improving the suppression of resistance. In this regard, a group of uniform materials based on organic salts (GUMBOS) presents an alternative to this problem allowing the combination of antibacterials with adjuvants. Fluoroquinolones are a family of antibacterials used to treat respiratory and urinary tract infections with broad-spectrum activity. Ciprofloxacin and moxifloxacin-based GUMBOS were synthesized via anion exchange reactions with lithium and sodium salts. Structural characterization, thermal stability and octanol/water partition ratios were evaluated. The antibacterial profiles of most GUMBOS were comparable to their cationic counterparts when tested against Gram-positive S. aureus and Gram-negative E. coli, except for deoxycholate anion, which demonstrated the least effective antibacterial activity. Additionally, some GUMBOS were less cytotoxic to L929 fibroblast cells and non-hemolytic to red blood cells. Therefore, these agents exhibit promise as an alternative approach to combining drugs for treating infections caused by resistant bacteria.

Moxifloxacin Metal Complexes: Synthesis, Characterisation, Antimicrobial and Antidiabetic Activities with Docking Studies

Six new metal complexes of Fe(III), Cu(II), and Hg(II) were synthesised, i.e., three (2, 4, and 5) with moxifloxacin (mono-ligand) and the other three (1, 3 and 6) with moxifloxacin and hydrazine (biligand). These were characterised through UV-Vis, FT-IR, elemental analysis (CHN), atomic absorption spectroscopy, TGA, scanning electron microscopy (SEM), and powder XRD studies. Further, all of these compounds were screened for their antimicrobial, cytotoxic, and antidiabetic potential. The study revealed that the synthesised metal complexes possess an excellent ability to become antifungal agents compared to moxifloxacin. Additionally, the cytotoxicity of compounds 1, 3, and 4 was in the acceptable range with much better antidiabetic potential as compared to the ligand moxifloxacin. Interestingly, the α-amylase inhibition activity of complexes 1 and 3 was found very close to the standard drug acarbose. Furthermore, the computational studies also authenticate the results of the antidiabetic potential of complexes 1, 3, and 4 by presenting the necessary interactions of these compounds with their respective binding sites. The overall results indicate that the antifungal and antidiabetic ability of moxifloxacin is enhanced significantly by complexation with the given metals and the secondary ligand, thereby making it a suitable lead compound for yet another avenue of an antifungal and antidiabetic agent in the field of drug discovery and development.

Enhancing efficacy of existing antibacterials against selected multiple drug resistant bacteria using cinnamic acid-coated magnetic iron oxide and mesoporous silica nanoparticles

Developing new antibacterial drugs by using traditional ways is insufficient to meet existing challenges; hence, new strategies in the field of antibacterial discovery are necessary. An alternative strategy is to improve the efficacy of currently available antibiotics. Herein, the antibacterial efficacy of drugs (Cefixime, Sulfamethoxazole, and Moxifloxacin) and drug-loaded cinnamic acid-coated magnetic iron oxide and mesoporous silica nanoparticles (NPs) was elucidated versus Gram-negative bacteria (Pseudomonas aeruginosa, Klebsiella pneumoniae, neuropathogenic Escherichia coli K1 and Serratia marcescens) and Gram-positive bacteria (Methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pyogenes, Streptococcus pneumoniae, and Bacillus cereus). NPs were synthesized by co-precipitation and the Stöber method, and characterized by Fourier transform-infrared spectroscopy, Zetasizer, and Atomic force microscopy. Lactate dehydrogenase (LDH) assays were accomplished to determine drug cytotoxicity against human cells. Spherical NPs in the range of 118-362 nm were successfully synthesized. Antibacterial assays revealed that drugs conjugated with NPs portray enhanced bactericidal efficacies against multiple drug resistant bacteria compared to the drugs alone. Of note, Cefixime-conjugated NPs against Escherichia coli K1 and Methicillin- resistant Staphylococcus aureus, resulted in the complete eradication of all bacterial isolates tested at significantly lower concentrations compared to the antibiotics alone. Likewise, conjugation of Moxifloxacin resulted in the complete elimination of E. coli K1 and MRSA. Of note, nano-formulated drugs presented negligible cytotoxicity against human cells. These results depict potent, and enhanced efficacy of nano-formulated drugs against medically important bacteria and can be used as alternatives to current antibiotics. Future in vivo studies and clinical studies are warranted in prospective years to realize these expectations.

The antibacterial activity of fluoroquinolone derivatives: An update (2018-2021)

Bacterial infection is amongst the most common diseases in community and hospital settings. Fluoroquinolones, exerting the antibacterial activity through binding to type II bacterial topoisomerase enzymes, DNA gyrase and topoisomerase IV, are mainstays of chemotherapy. At present, fluoroquinolones are the most valuable antibacterial agents used popularly. However, the emergence of more virulent and resistant pathogens by the development of either mutated DNA-binding proteins or efflux pump mechanism for fluoroquinolones results in an urgent demand to develop new fluoroquinolones to withstand the drug resistance and to obtain a broader spectrum of activity. This review aims to outline the recent advances of fluoroquinolone derivatives with antibacterial potential and to summarize the structure-activity relationship (SAR) so as to provide an insight for rational design of more active candidates, covering articles published between January 2018 and June 2021.

Discovery of a Dimeric Zinc Complex and Five Cyclopentenone Derivatives from the Sponge-Associated Fungus Aspergillus ochraceopetaliformis

In devotion to investigating structurally novel and biologically active marine natural products, a dimer of a zinc complex, dizinchydroxyneoaspergillin (1), aspernones A-E (2-6), five cyclopentenone derivatives together with known polyketides (7-10), and neoaspergillic acid analogues (11-14) were isolated from the sponge-associated fungus Aspergillus ochraceopetaliformis SCSIO 41018. Their structures were elucidated on the basis of spectroscopic analysis, electronic circular dichroism (ECD) analysis, and X-ray diffraction. Dizinchydroxyneoaspergillin (1) displayed significant bactericide effects toward methicillin-resistant Staphyloccocus aureus, Staphyloccocus aureus, Enterococcus faecalis, Acinetobacter baumannii, and Klebsiella pneumonia with MIC values of 0.45-7.8 μg/mL and moderate in vitro cytotoxic activities against the K562, BEL-7402, and SGC-7901 cell lines with IC₅₀ values of 12.88 ± 0.14, 15.83 ± 0.23, and 15.08 ± 0.62 μM, respectively. This is the first time to report the dimer of the zinc complex of hydroxyneoaspergillic acid conjunction at Zn-N-4 by a coordination bond. Additionally, compound 1 displayed significant antibacterial and cytotoxic activities, which would be a promising drug lead and could attract much attention from both chemists and pharmacists.

Biological Investigations and Spectroscopic Studies of New Moxifloxacin/Glycine-Metal Complexes

Two novel ligand-metal complexes were prepared through the reaction of Zn(II) and Sn(II) with moxifloxacin (MOX) in the presence of glycine (Gly) to investigate their biological activities. IR, UV/VIS and ¹ H-NMR analysis have been carried out for insuring the chelation process. Results suggested that MOX and Gly react with the metal ions through the carbonyl oxygen atom and the oxygen atom of the carboxylic group of MOX and Gly. The antimicrobial activity was carried out against some common bacterial and fungal pathogens and the radical scavenging activity (RSA%) was evaluated using DPPH and ABTS methods. Phytotoxic effect of the prepared complexes was evaluated in vitro against Raphanus raphanistrum and Lepidium sativum. Hemolytic activity was tested against cell membrane of erythrocytes. Results showed that the two prepared complexes exhibited high antimicrobial activity against all tested phytopathogens and no significant phytotoxic effect has been observed. Only MOX-Zn(II) complex showed moderate hemolysis at 100 % concentration.